My legs are sore and my face is so red. Why is this happening?

Yesterday, I saw my legs get red and I quickly took some syrup and it got better so I was relieved, but my cheeks had been red since last time, but today they suddenly got really bad. I thought it was just dryness and cracking because it was winter, but I ate something wrong and it's slightly red all the way down to my chinㅜ I heard that an allergy from eating the wrong food usually breaks out like hives all over the body, but my torso doesn't, so I wonder what's causing itㅜㅜ

I'm going to go to the hospital tomorrow, but I'm worried. I'm hesitant to go to the emergency room. I went to the emergency room because I thought I had an allergy like this before, but they just sent me away. I think I need to get some over-the-counter medication in advance.

If anyone has ever experienced a child suddenly sucking their cheek or leg like this, please give me some good information.

The red bumps on the legs are like when you put something warm on them and then take them off... I can't explain it, but anyway, they don't come up like hives.

Do you know of any over-the-counter medicines?